Selecting Hot-Melt Adhesive Products

Color requirements for the adhesive may vary. Unless the substrates have specific color requirements, yellow hot-melt adhesive is recommended; generally, yellow hot-melt adhesive offers superior bonding strength compared to the white variety.

 

Surface preparation of substrates. While hot-melt adhesives are less demanding regarding surface preparation than other types of adhesives, dust and oil on the substrate surfaces should still be properly treated to ensure optimal bonding performance.

 

Application time. Rapid application is a key characteristic of hot-melt adhesives. The typical application time is around 15 seconds; however, the widespread adoption of modern assembly-line production methods has created a demand for shorter application times-for instance, processes such as bookbinding and speaker manufacturing often require application times of approximately 5 seconds.

 

Temperature resistance. Hot-melt adhesives are sensitive to temperature. They begin to soften when exposed to high temperatures and become brittle at low temperatures; therefore, temperature fluctuations in the product's operating environment must be carefully considered when selecting an adhesive.

 

Adhesion. Adhesion properties are categorized into initial tack and final bond strength. A stable bond between the adhesive and the substrate is achieved only when both the initial tack and final bond strength are consistent. During production, the adhesive should be formulated to ensure resistance to oxidation, halogens, and acids/alkalis, as well as appropriate plasticizing properties. Since adhesion performance varies depending on the substrate material, the specific hot-melt adhesive chosen should be matched to the material in question.